A large shareholder is seeking to get at least two board seats at Ariad Pharmaceuticals Inc , the drugmaker grappling with safety concerns involving its leukemia drug Iclusig, according to people familiar with the matter. Sarissa Capital Management LP, an activist fund run by Alex Denner - investor Carl Icahn's former healthcare lieutenant - disclosed in October that it has taken a 6.2 percent stake in Ariad, becoming the company's second-largest shareholder. Sarissa has spoken to the biotechnology company about adding a few of its own directors to the board and is interested in reaching a settlement before a proxy deadline, the people said, asking not to be named because the matter is private.